only making 4 psi....

[dabigbolf]

hey,

hooked up the boost gauge. And i am only getting 4 psi as a reading.

What could this be. Its a series 1 motor.

all hoses seem to be connected.

[meggala]

boost gauge could be wrong

when you can put it on a dyno to get it full checked out

[dabigbolf]

i am getting the engine cutting out on me when i am driving....

It does seem that that 4 psi could be right. As it sort of spools up, but doesn't really throw you back in the seat at all....

Theres just a lot of sounds....... spool up noises, which probly exagerates the power its putting down.

i am using the 040 bosch fuel pump, which seems to be doing fine...

dyno might be the best option.

[rob77]

go to a dyno this is what they are best used for, diagnosing problems, checking afr's, checking boost etc.

[GTS-t VSPEC]

Sounds like a boost leak. The turbo is spooling, and the AFM is sensing the airflow, but it's leaking out before the plenum, therefore too much fuel is added, and can cause the engine to cut etc.

Get it to the dyno, the safest way.

[dabigbolf]

i gotta do the clutch again. Bleed it up.

and then take it to a dyno.

I am really unsure of which guys to go for.

BMT seem to have a good reputation.

what sort of price would i be looking at.....

[2rismo]

leaking BOV?

Adrian

[gtrhybrid]

check your timing. If your detonation sensors are sensing detonation before 3500 rpm they will send you to SAFTEY BOOST which could be 4psi for your car. For that matter other sensors or an engine light will do the same. Good luck.

[Col-GTSX]

id say leaky BOV does it sound like its making more than that or is it really only making 4psi... i mean do you know the feeling difference between say 10 and 4psi....

[Col-GTSX]

No offence intented just does it sound like its higher.. cause if it is higher and the performance is there id say blocked or more to the point restricted line to the boost gadge....

[dabigbolf]

well, it does go.

theres no leaky bov... as i am not running one...

I have no tacho on it, so its hard to estimate revs. But say boost hits at 2800 rpm. I get around 4 psi up to around 4700 rpm. the boost stays there. Then from 4700 rpm it boost to 7 or 8 psi. That would be revving it to say 5500 rpm or so.

But you can notice that the boost gauge needle sits on 4 psi for a long time. More than what i have seen in other peoples r33's.

I rechecked the boost line gauge, and that seems fine.

Only problem i am seeing is that the boost is staying at 4 psi for a fair bit. Theres no fuel pump issues, as the car has a bosch 040.

The timing may be a problem. But i am pretty postive that we have set the timing back....

What is the normal state for the timing to be set at, and how can i tell when setting it. I have the crank angle sensor where the screws are pretty close to being retarded timing.

i do have a simple boost bleed valve, that i could install, but would like to get it running righyt first.

What sort of boost should i be getting and at what rev range.

e.g psi@? revs...

cheers

[Steve]

Stock RB25 skyline boost is 5psi to 5000rpm, then 7 psi to redline. Its 2 stage. If your boost guage is inaccurate (its not an autometer is it? they seem to go out of cal), that would account for the 4 psi instead of 5.

Usually when a cat back is fitted the drop in back pressure gives another couple of pounds boost, but then you get 7psi to 5000rpm and 9 psi to redline.

This is standard without a good EBC or bleeder.

[dabigbolf]

ah, well thanks. I dont like it. 5 psi to 5000 rpm sucks. i dont really like revving the car out to redline. But at least in know nothing is buggered,

I have the stock dump pipe, but everything else 3 inch. Also have front mount intercooler.

I do have a liquid filled autometre boost gauge, and i'd say it goes to around 4 psi then to 8 psi.

So 5 and 9 psi you seem to be correct.

If i was wanting to get the boost to come on earlier would using the bleed valve do this. Where do i set it up from. Never really used one before. DO i t piece the valve just after the actuator hose, and tehn run that up to a plenum nossel....

And having the bleed valve tightened, or loosened has what effect. Upping or lowering the boost.

11 or 12 psi would be what i would run on the standard turbo.

[Steve]

4 seems a bit low if you have 3" back except the dump, but 9 seems about right.

I have never connected up a bleed valve, only an EBC, so sorry I cant help there. Pretty sure that tightening the valve will restrict air, thereby increasing boost, which is what you want as it is boost pressure that opens the wastegate.

[dabigbolf]

think theres a stock boost controller that has to be disconnected...

maybe someone else can elaborated.

[Steve]

Pretty sure that you dont disconnect the stock controller, just restrict the air to it, or between it and the wastegate.